any idea what error 3503 is?

it's work now , I was trying it one hour ago and worked

Bonus!

I have the same problem with my Iphone 6S Plus. Do you solved it?

I did the same but was able to update without having to restore. Thanks!

how do you turn it off through icloud find my iphone ??

got got, going to try right now

i have a iPhone 5 to restore ios 11

it is something that got to do with SHSH i think

THANKS GUYS

THANKS

THANKS

IT WORKED

THANKS APPLE ENGINEERS

THANKS EVERYONE

iPhone 3505 Error How to Solve? - YouTube

Doing this caused us to lose all of our child's first videos. When we selected this it erased everything from our ipad. 😟 I spent the entire evening crying.

I'm noticing a lot of people received this error when updating. I wasn't updating, I updated to 11 on Tuesday. My phone was plugged in on my nightstand and I went to use it a few hours later and it was on the apple screen (it was fine when I plugged it in to charge). I cannot update or restore my phone via itunes. On PC I get code 3503. On Mac it just sits indefinitely "waiting" for the iphone in the restore process. Neither the rep, nor there supervisor were able to help. My phone just keeps randomly cycling between the apple logo screen and a black backlit screen (when I don't force it to the restore screen). Their solution was to schedule me to go to the apple store tomorrow.

My issue started two days ago when I tried to download music from Apple Music back onto my phone. The downloads froze half way through and then my Music app, and going into Music under settings, would both crash my phone. My first step was to try restore my phone using iTunes on a Windows 10 PC and thats when the error 3503 started.

I tried all the apps everyone has spoken about but none worked. I tried my phone in recovering mode and DFU mode but still nothing worked.

I spoke to Apple Support in California and sent them all my logs. I advised them of this thread as it was gaining traction and they advised they are looking into the issue.

This morning I put my phone into recovery mode again and connected it to iTunes and chose to Update. I received an error 2003. I put my phone into recovery mode again and connected it to iTunes and chose to Restore.

It has now successfully restored itself back to factory default settings and then used a previous iTunes backup to restore apps etc.

Take a look at these articles:

Resolve iOS update and restore errors in iTunes - Apple Support

Get help with iOS update and restore errors - Apple Support

Try If you can't update or restore your iPhone, iPad, or iPod touch - Apple Support.

tt2